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Vernonv
8th August 2012, 08:21 PM
Hi all,
I need help. I went to do some threading tonight and the gear train wouldn't work.

It's a Nuttall lathe. When in position II everything works fine, but in position I I get no move gear train movement.

As you can see in the photo below, position 1 is an 8 by reduction of position 2.
http://www.woodworkforums.com/attachment.php?attachmentid=218804&stc=1&d=1344417112

Here is the lever that switches between position 1 and 2.
http://www.woodworkforums.com/attachment.php?attachmentid=218805&stc=1&d=1344417112

This is position 2. Gear 1 and 2 are on the main shaft. Gear 3 is an idler that switches between pos 1 and 2. Gear 2 is fixed to the main shaft.
http://www.woodworkforums.com/attachment.php?attachmentid=218807&stc=1&d=1344417112

This is position 1. Gear 1 must move at an 8:1 reduction compared to the main shaft - I'm not sure how, could it be some kind of planetary gear???? Anyway gear 1 just seems to turn i.e. it's like it's not connected to anything.
http://www.woodworkforums.com/attachment.php?attachmentid=218806&stc=1&d=1344417112


Any ideas? Will I have to pull down the main shaft?

shedhappens
8th August 2012, 08:27 PM
hi Vernonv,

what are those two gears to the right of your number three ?

shedhappens
8th August 2012, 08:29 PM
sorry, I mean the smaller ones

Bryan
8th August 2012, 08:46 PM
Have you used pos 1 before? Sounds like gear 1 has sheared a pin or spat a key...

steran50
8th August 2012, 08:47 PM
HI:),
I am not familiar with these Lathes, but I wondering whether there is not supposed to be a Pin or something in the Slot between No1 and No.2 Gears. This Link is apparently the Australian Supplier of Nuttall Lathe Parts B & D Machining Pty Ltd: Nuttall Lathe Parts (http://www.bdmachining.com.au/nuttall-lathe-parts/) . I doubt that it would have Planetary Gears, I suspect that a Key for a Keyway or Pin may have Sheared off. I suggest you Drain the Oil and see if anything comes out or if this anything at the bottom of the Sump.

.RC.
8th August 2012, 08:49 PM
Are you sure they are not the feed reverse gears?

Does the interlock work.... In the coarse feed rates you should not be able to select the high spindle speed...

Vernonv
8th August 2012, 09:48 PM
hi Vernonv,

what are those two gears to the right of your number three ?You mean the ones in the front? They are for the gear train - forward and reverse.

Vernonv
8th August 2012, 09:49 PM
Have you used pos 1 before? Sounds like gear 1 has sheared a pin or spat a key...Yep, just the other day. I'm thinking you are right about the sheared pin/key. I think I will have to strip it down.

Vernonv
8th August 2012, 09:53 PM
Are you sure they are not the feed reverse gears?

Does the interlock work.... In the coarse feed rates you should not be able to select the high spindle speed...The reverse gears are in front and down.

Interlock? ... I didn't know it had one. I will have to have a look at that. However I never run the coarse threads on a fast speed.

Bryan
8th August 2012, 09:58 PM
Do you have info on the spindle bearings? Like how to adjust them?

Oldneweng
8th August 2012, 10:03 PM
Vernon if you need I can pull the top off mine tomorrow night and check gear movement etc. Also note that I will soon have a spare Nuttall for sale.

Dean

.RC.
8th August 2012, 10:27 PM
The reverse gears are in front and down.

Interlock? ... I didn't know it had one. I will have to have a look at that. However I never run the coarse threads on a fast speed.

Ahh yes I see that now about the reverse gears...

I had a nuttall like that many years ago and like most lathes you could not select the coarse feed and high speed... I see it even says on the plate next to the II "Available with slow spindle only"

I would have thought with a sheared key it would still be stiffish and not free running...

With both gears at the same size it means they are not supposed to spin at the same speed..

Are there any gear trains hidden directly under the spindle hidden under the oil?

Would you have a picture of the entire headstock gears?

shedhappens
8th August 2012, 11:03 PM
RC said,
"I see it even says on the plate next to the II "Available with slow spindle only"

it seems funny, the lever to the right is in the fast position, so by my way of thinking that feed gear should not have engaged in position 2 ?

or was it not in that position when testing the gears ?

Vernonv
9th August 2012, 08:00 AM
Hi all,
Thanks all. Just a quick update - it was a sheared key.

http://www.woodworkforums.com/attachment.php?attachmentid=218835&stc=1&d=1344459535

http://www.woodworkforums.com/attachment.php?attachmentid=218836&stc=1&d=1344459535


Anyone have any tips on how best to adjust the tapered roller bearings on reassembly?


:)

Vernonv
9th August 2012, 08:45 AM
Vernon if you need I can pull the top off mine tomorrow night and check gear movement etc. Thanks for the offer, but I'm right for now.

Vernonv
9th August 2012, 08:50 AM
I would have thought with a sheared key it would still be stiffish and not free running...Yes, It was a little stiffish.


With both gears at the same size it means they are not supposed to spin at the same speed..That was my assumption also. It turns out that the main gears are actually free on the main shaft and the gear with the broken key isn't (or shouldn't be). The gear reduction actually happens at the other end of the headstock.


Are there any gear trains hidden directly under the spindle hidden under the oil? only the forward and reverse gears. I did drain the headstock - nothing foreign in it at all ... very clean actually ... certainly no Chinese casting sand :).


Would you have a picture of the entire headstock gears?No don't, but could get one tonight.

Vernonv
9th August 2012, 09:34 AM
RC said,
"I see it even says on the plate next to the II "Available with slow spindle only"

it seems funny, the lever to the right is in the fast position, so by my way of thinking that feed gear should not have engaged in position 2 ?

or was it not in that position when testing the gears ?Yes, that was just me moving levers, spinning gears (by hand), etc, to try and figure out how the gearbox worked. Once I get it back together I will check out the "interlock" that RC mentioned.

whitey56
9th August 2012, 09:39 AM
As a mechanic for 40 yrs this is the way i do wheel brgs
Make sure the brg cones are seated with hammer and punch, if they are turning in their housings Loctite them in.
Assemble shaft and cones and tighten nut firm,spin the shaft and back off the nut till loose, then retighten nut using 1 finger on the wrench to preload the brgs you are looking for about 1/3 the pressure of your first tighten.
If you are using new bearings i would use 2 fingers to allow for bedding in, you could use lite oil on brgs during assembly.
Diff reconditioners would use a spring gauge to set preload [ something like Scales to weigh a fish] in the old days, you could search the Web to set preload this way.

Hope this helps.

Bryan
9th August 2012, 09:44 AM
Anyone have any tips on how best to adjust the tapered roller bearings on reassembly?

Machtool Phil is your man. Until he comes along some searching will keep you busy, especially on PM. Is it just a single bearing at each end? As I understand it there are two main ways to measure preload: rolling torque and temperature rise. You should be able to hold your hand on the housing after extended running at high speed. But if it's not fairly warm they're too loose.

Vernonv
9th August 2012, 12:25 PM
As a mechanic for 40 yrs this is the way i do wheel brgs
Make sure the brg cones are seated with hammer and punch, if they are turning in their housings Loctite them in.
Assemble shaft and cones and tighten nut firm,spin the shaft and back off the nut till loose, then retighten nut using 1 finger on the wrench to preload the brgs you are looking for about 1/3 the pressure of your first tighten.
If you are using new bearings i would use 2 fingers to allow for bedding in, you could use lite oil on brgs during assembly.
Diff reconditioners would use a spring gauge to set preload [ something like Scales to weigh a fish] in the old days, you could search the Web to set preload this way.

Hope this helps.Ok, I've done a a few wheel bearings, so can see where you are coming from. I have on occasion used the spring gauge to check preload, when I know what the figure should be. Trouble is this is an old lathe (1948) and I don't have any technical info on it.


Machtool Phil is your man. Until he comes along some searching will keep you busy, especially on PM. Is it just a single bearing at each end? As I understand it there are two main ways to measure preload: rolling torque and temperature rise. You should be able to hold your hand on the housing after extended running at high speed. But if it's not fairly warm they're too loose.There are two tapered roller bearings in the chuck (right) end of the housing (one on the outside and one on the inside of the housing wall) and a non-tapered roller bearing (or maybe very slightly tapered) on outside of the left end of the housing.

Bryan
9th August 2012, 03:19 PM
Mine has the opposed pair at the front too. Here is my thread on PM about adjusting mine: Do Graziano Spindle Bearings Need Adjustment? (http://www.practicalmachinist.com/vb/schaublin-cazeneuve-weiler-graziano-mori-seiki-lathes/do-graziano-spindle-bearings-need-adjustment-234363/). Phil weighs in at #20. YMMV.

Vernonv
9th August 2012, 03:49 PM
Thanks Bryan (and Phil) ... sounds like the way to go. Will give it a go tonight when I reassemble.

Vernonv
10th August 2012, 09:58 AM
Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ... :doh::B

Steamwhisperer
10th August 2012, 10:39 AM
Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ... :doh::B

Great Vernon,
At least I'm not the only to do that.
Woo Hoo.

Phil

Vernonv
10th August 2012, 10:43 AM
Great Vernon,
At least I'm not the only to do that.
Woo Hoo.

PhilMakes one hell of a "rooster tail". Luckily I hit the clutch lever quickly and minimised the mess ... and I wasn't standing directly in front of it.

Stustoys
10th August 2012, 11:30 AM
"Splash lubrication?" "checked" :D

Steamwhisperer
10th August 2012, 12:09 PM
It's an outstanding splash.

HavinaGo
10th August 2012, 12:39 PM
Ok, job done. Thanks all for your input.

... and here's a tip for you - don't start the lathe with the clutch disengaged, the lid off and the headstock full of oil ...

Pleased to hear things fixed

Must say the splash is something I'd fall for based on past history -

I've done it with cars
I was used to push rod engines, then worked on a new-fangled overhead cam engine - started it to see if thinks were right - they were and the oil pump worked well
- the chain driving the cam shaft that is ---- :B

steran50
10th August 2012, 01:51 PM
HI:),
Glad to Hear You got it Sorted and glad to Hear that You avoided the Oil.